1. Field of the Invention
The present invention relates to a configuration applicable to flat panel displays represented by active matrix liquid crystal displays and EL type displays.
2. Description of Related Art
Conventional known flat panel displays include active matrix liquid crystal displays having a configuration wherein a thin film transistor for switching is provided to each of a number of pixels provided in the form of a matrix and wherein charge going in and out each pixel electrode is controlled by the thin film transistor.
In such a configuration, a masking means (a light shielding means) must be provided to prevent light from entering the thin film transistors provided in a pixel region.
A metal film is currently chosen as the masking means (the light shielding means)from the viewpoint of dispersion of impurities and stability. Further, such a masking means for thin film transistors is generally provided to serve also as a black matrix which covers peripheral edge regions of pixel electrodes.
Such a configuration has the following problems. The first problem is that a capacity is generated between the masking film and the thin film transistors, and this adversely affects the operation of the thin film transistors. The second problem is that since the masking film is generally formed on a substrate having irregularity thereon which can make the masking function insufficient.
The problem associated with the masking function equally applies to the black matrix provided so as to overlap with the edges of pixels.
It is an object of the invention disclosed in this specification to provide a configuration which solves the problems associated with a masking film for shading thin film transistors to achieve high performance as an active matrix display.